Abstract
A fluid injection device of the jet stream type, comprising: —a housing defining a fluid collection chamber and having a nozzle; —a coupler for coupling the fluid injection device with a fluid container; —a piston head configured to be received and movable in the housing, to increase and decrease a volume thereof; —a piston rod, coupled to the piston head and having an internal flow channel, which extends from the piston rod for penetration of the fluid container, the piston head including a valve made of an elastically deformable material and comprising a radial flow channel, the radial flow channel being open when the piston head is moved in a fluid collection chamber volume increasing direction and the radial flow channel being closed by an elastic deformation of the valve material when the piston head is moved in a fluid collection chamber volume decreasing direction.
Claims
1. A fluid injection device (1) of the type that injects fluid in a skin of a patient by ejecting a jet stream of fluid, the fluid injection device (1) comprising: a housing (12) having an outlet nozzle (121), the housing (12) defining a fluid collection chamber (122) for collecting fluid to be ejected, the fluid collection chamber (122) being in fluid communication with the outlet nozzle (121); a coupler (14) for coupling the fluid injection device (1) with a fluid container (3, 5), preferably in a releasable manner; a piston head (13) configured to be received in the housing (12), the piston head (13) being movable in the housing (12) to increase and decrease a volume of the fluid collection chamber (122); a piston rod (16), coupled to the piston head (13) and having an internal flow channel (15), wherein the flow channel (15) of the piston rod (16) extends with respect to said piston rod (16) for penetration of the fluid container (3, 5), so as to provide a flow path from said fluid container (3, 5) to said piston head (13), and wherein the piston head (13) includes a valve (131) that has an open (O) and closed (C) position, the valve (131) being made of an elastically deformable material and comprising a radial flow channel (133) that provides a flow path from the piston head (13) to the fluid collection chamber (122), the radial flow channel (133) of the valve (131) being open when the piston head (13) and piston rod (16) are moved in a direction that increases the volume of the fluid collection chamber (122) and the radial flow channel (133) of the valve (131) being closed by an elastic deformation of the elastically deformable valve material when the piston head (13) and the piston rod (16) are moved in a direction that decreases the volume of the fluid collection chamber (122).
2. The fluid injection device according to claim 1, wherein the valve (131) is made of an elastomeric material or a rubber, e.g. a thermoplastic elastomer (TPE), a synthetic rubber or a natural rubber.
3. The fluid injection device according to claim 2, wherein the elastomeric material or the rubber has a hardness of between 70 and 100 Shore A.
4. The fluid injection device according to claim 1, further comprising a cap (11) configured to be coupled with the fluid injection device (1), the cap (11) including a seal (111) for sealing the outlet nozzle (121).
5. The fluid injection device according to claim 4, wherein the seal (111) seals the outlet nozzle (121) in a liquid- and air-tight manner when the cap (11) is coupled with the fluid injection device (1).
6. The fluid injection device according to claim 1, wherein the piston head (13) and the piston rod (16) are coupled to each other via a threaded connection (17).
7. The fluid injection device according to claim 6, wherein the piston head (13) has a piston rod receiving chamber (135) for receiving the piston rod (16) therein, and wherein the internal flow channel (15) of the piston rod (16), when seen in longitudinal direction (L) of said piston rod (16), extends beyond the threaded connection (17).
8. The fluid injection device according to claim 1, wherein the piston head (13) has a piston rod receiving chamber (135) for receiving the piston rod (16) therein, and wherein the internal flow channel (15) of the piston rod (16), when seen in longitudinal direction (L) of said piston rod (16), extends beyond the location of the radial flow channel (133).
9. The fluid injection device according to claim 1, wherein a fluid container facing end (151) of the flow channel (15) has a sharp end configured for penetrating a septum (31) of the fluid container (3, 5).
10. The fluid injection device according to claim 9, wherein the flow channel (15) is defined by a needle, the sharp end of the needle facing the fluid container (3, 5).
11. The fluid injection device according to claim 1, wherein the coupler (14) comprises snap fingers (141) for receiving the fluid container (3, 5) therein.
12. The fluid injection device according to claim 1, wherein the coupler (14) comprises a female Luer taper thread (143).
13. The fluid injection device according to claim 1, wherein the valve (131) further comprises a seal ring (134), positioned behind the radial flow channel (133) when seen in a longitudinal direction (L) of the piston rod (16), the seal ring (134) being in contact with an inner wall (124) of the fluid collection chamber (122).
14. The fluid injection device according to claim 1, wherein the valve (131) comprises an annular rim (132) which is in contact with an inner wall (124) of the fluid collection chamber (122) with at least a part of its outer circumference, the annular rim (132) being made of said elastically deformable material and having throughflow openings (137), the annular rim (132) being positioned in between the radial flow channel (133) and the outlet nozzle (121) in an assembled state of the fluid injection device (1), wherein in use a forwards movement (F) of the piston head (13) results in a closing of the radial flow channel (133) due to friction (FF) between the annular rim (132) and the inner wall (124) of the fluid collection chamber (122), while in use a backwards movement (B) of the piston head (13) results in an opening of the radial flow channel (133) due to friction (FF) between the annular rim (132) and the inner wall (124) of the fluid collection chamber (122).
15. A fluid injection assembly (100) comprising a fluid injection device (1) according to claim 1, further comprising a fluid container (3, 5), the fluid container (3, 5) being coupled to the fluid injection device (1) via the coupler (14).
16. The fluid injection assembly according to claim 15, wherein the fluid container (3, 5) comprises a piston head (33, 52).
17. The fluid injection assembly according to claim 16, further comprising an actuator for moving the piston head (33) of the fluid container (3) in a direction towards the fluid injection device (1), said movement resulting in a flow of fluid from the fluid container (3) towards and into the fluid collection chamber (122) of the fluid injection device (1).
Description
[0050] These and other aspects of the invention will now be elucidated further with reference to the attached Figures. The Figures will indicate like or same features with the same reference numerals. In these Figures:
[0051] FIG. 1 schematically shows a longitudinal cross-sectional view of a fluid injection assembly according to the present invention;
[0052] FIG. 2 schematically shows in isometric view a detailed view of the piston head, the piston rod, and the coupler of the fluid injection assembly of FIG. 1;
[0053] FIG. 3 schematically shows a longitudinal cross sectional view of the piston head, the piston rod, and the coupler of FIG. 2;
[0054] FIG. 4 schematically shows a view along a longitudinal cross section of the valve of the fluid injection device of FIG. 1, the valve being in open position;
[0055] FIG. 5 substantially corresponds to FIG. 4 and highlights the forces and the fluid flow;
[0056] FIG. 6A schematically shows in a front isometric view the fluid flow around an embodiment of a valve of the fluid injection device and assembly according to the present invention, the valve being in its open position;
[0057] FIG. 6B substantially corresponds to FIG. 6A but omits the fluid flow indications;
[0058] FIG. 7 schematically shows a view along a longitudinal cross section of the valve of FIG. 4, the valve being in a closed position;
[0059] FIG. 8 schematically shows a second embodiment of a fluid injection assembly according to the invention, in a longitudinal cross sectional view;
[0060] FIG. 9 schematically shows a third embodiment of a fluid injection assembly according to the invention, in a longitudinal cross sectional view; and
[0061] FIG. 10 schematically shows one possible manufacturing process of the valve of the fluid injection device and assembly according to the present invention.
[0062] With respect to FIGS. 1, 2 and 3, which are described simultaneously, FIG. 2 shows a cross sectional view along a longitudinal axis of a fluid injection assembly 100. Shown in FIG. 2 is an isometric view of a part of the injection assembly, most importantly coupler 14, piston rod 16 and piston head 13 including valve 131. FIG. 3 shows the same elements as FIG. 3, but in a cross sectional view along a longitudinal direction.
[0063] The fluid container 3 and the fluid injection device 1 are coupled via coupler 14. The fluid container 3, as shown herein, comprises an injection fluid IF, a piston head 33 at the rear side thereof, a septum 31 to cover an outlet of the fluid container 3, and a cap 32 to seal the septum 31 with respect to the fluid container 3.
[0064] It is noted that this fluid container is a relatively standard fluid container. The present invention is in no way limited to the use of a specific fluid container. Indeed, FIGS. 8 and 9 show other embodiments of fluid containers, even though the three shown embodiments are certainly not the only types of fluid containers with which the fluid injection device may be coupled.
[0065] The coupler 14 of FIGS. 1, 2 and 3 here comprises snap fingers 141 for coupling the fluid container 3 to the fluid injection device 1. It is noted that the present invention is in no way limited by the type of coupling used between the fluid container 3 and the fluid injection device 1. The use of snap fingers 141 is only one exemplary option of a multitude of options. Indeed, with reference to FIGS. 8 and 9, a Luer coupling is e.g. shown.
[0066] The coupler 14 further includes a flange 142, extending radially outwards with respect to the piston rod 16. The piston rod 16 and piston head 13 may e.g. be moved by applying a force on the flange 142.
[0067] The fluid injection device 1 shown in FIG. 1 is here coupled with a cap 11 which may protect an outlet 121 of the fluid injection device 1 when the fluid injection device 1 is not used. The cap 11 comprises a seal 111 for sealing the outlet 121 in an air-tight and fluid-tight manner. The cap 11 is coupled to the fluid injection device 1 via coupling mechanism 112, 123 which comprises a male part 123 associated with the housing 12 and a female part 112 associated with the cap 11. In embodiments, the cap 11 may e.g. be coupled with a housing 12 of the fluid injection device 1.
[0068] The fluid injection device 1 shown in FIG. 1 comprises a housing 12. The housing 12 is hollow, as e.g. better visible in FIG. 5, and defines a fluid collection chamber. At a frontal end of the housing 12, a nozzle outlet 121 is defined. The nozzle outlet 121, and thus also the fluid injection device 1, is of the type that allows an injection of fluid in a skin of a patient by ejecting a jet stream of fluid.
[0069] The fluid injection device 1 shown in FIG. 2 also comprises a piston head 13. In an assembled state of the fluid collection device 1, the piston head 13 is received inside the fluid collection chamber. The piston head 13 is moveable in a forwards F and backwards B direction, thereby reducing respectively increasing a volume of the fluid collection chamber. The front side of the piston head 13 is matched to the shape of the fluid collection chamber near the nozzle outlet 121, allowing the piston head 13 to reduce a volume of the fluid collection chamber to substantially zero in its foremost position. The piston head 13 includes a valve 131, which is described in more detail in the below, with reference to FIGS. 4-7.
[0070] The fluid injection device 1 shown in FIG. 1 also comprises a piston rod 16, coupled to the piston head 13 via a threaded connection 17 and received in the fluid collection chamber of the housing 12. Upon movement of the piston rod 16, e.g. via flange 142, both the piston head 13 and the piston rod 16 move in the fluid collection chamber. The piston rod 16 comprises an internal flow channel 15 which extends in the backwards direction B with respect to the piston rod 16, and extends into the fluid container 3. The internal flow channel 15 provides a flow path from the fluid container 3, through the piston rod 16, and into the piston head 13. The flow channel 15 is here embodied as a needle, having a sharp end at the side facing the fluid container 3, allowing the needle to penetrate the septum 31 of the fluid container 3. Even though the connection between the piston rod 16 and the piston head 13 is here of the threaded type 17, many alternative connections between a piston rod 16 and a piston head 13 are known, and the invention is not limited to a particular type of connection.
[0071] As also shown with respect to FIGS. 2 and 3, the coupler 14 and the piston rod 16 may be made as one part.
[0072] With reference to FIGS. 2 and 3 mainly, piston head 13 includes a valve 131. The valve 131 as shown here includes a seal ring 134, radial flow channels 133, and annular rim 132 including throughflow openings 137. The valve 131 is made of an elastically deformable material, e.g. an elastomeric material such as a thermoplastic elastomer (TPE) or a rubber such as a synthetic rubber or a natural rubber. For example, the elastically deformable material of the valve 131 has a hardness of between 70 and 100 Shore A. In FIG. 3, the radial flow channels 133 are shown in their closed position C. Because of the elastic deformability of the piston head 13 material, the parts of the piston head 13 in front of the radial flow channel 133 and rearward of the radial flow channel 133 can move with respect to each other (and with respect to the piston rod 16) to open and/or close the radial flow channel 133.
[0073] The working of the valve 131 is now described in more detail, with reference to FIGS. 4-8 which are discussed together.
[0074] Shown in FIG. 4 is a more detailed view of the piston head 13 including valve 131, here in the open position O. The piston head 13 is coupled to the piston rod 16 via threaded connection 17. In the interior of the piston rod 16, a flow channel 15 is provided. The flow channel 15 extends between two ends of the piston rod 16, as the piston rod 16 is hollow. When a fluid container is coupled to the injection device, fluid can flow through said flow channel 15, as shown here. Piston head 13 comprises a piston rod receiving chamber 135 in which the piston rod 16 is received when the piston rod 16 and the piston head 13 are coupled. As shown here, the internal flow channel 15 runs along the entire length of the piston rod 16 and mouths in the piston rod receiving chamber 135 of the piston head 13 via a flow channel outlet arranged at a frontal side of the flow channel 15. When seen along a longitudinal direction of the piston rod, the flow channel outlet is arranged beyond the location of the threaded connection 17, and also beyond the radial flow channel 133.
[0075] As also illustrated in FIG. 5, the flow path of the fluid extends radially outwards from the piston rod receiving chamber 135, and backwards along an outside of the piston rod 16 through longitudinal flow channels 136, towards the radial flow channels 133. The fluid then flows radially outwards through radial flow channels 133, here in the open position O, and is forced past recesses 137 arranged in the annular rim 132 (see FIGS. 6A and 6B), into the fluid collection chamber 122. The annular rim 132 of piston head 13 includes recesses 137, here arranged on the radially outer side of the piston head 13, which serve as axial flow channels to allow fluid to flow from the radial flow channel 133 to the fluid collection chamber 122. A seal ring 134 prevents the fluid to flow in the backwards direction B again after is has flowed out of the radial flow channel 133.
[0076] As shown in FIG. 5, the valve 131 is in the open position O when the piston head 13 and piston rod 16 are moved in a backwards direction B, i.e. away from nozzle outlet 121 and increasing the volume of the fluid collection chamber 122. The open position O is here achieved by two forces which face in opposite directions. On the one hand, there is a friction force F.sub.F between the annular rim 132 of the valve 131 and the inner wall 124 of the fluid collection chamber, which are in contact with each other. On the other hand, there is a backwards pulling force F.sub.B effected by the backwards movement of the piston rod 16. The opposing forces result in an opening of the radial flow channel 133, and hence an opening of the valve 131.
[0077] In contrast, as illustrated in FIG. 7, when the piston rod 16 and piston head 13 are moved in a forwards direction F, towards the outlet nozzle and decreasing the volume of the fluid collection chamber, the valve is in the closed position C. An injection force F.sub.I deforms the part of the valve which is connected to the piston rod, while a friction force F.sub.F between the annular rim and the inner wall of the fluid collection chamber deforms the forward part of the valve. The combined effect of these deformations result in a compression and closing of the radial flow channel. Also the flow path from the piston rod receiving chamber to the radial flow channel may be compressed and closed to a more or less degree by these cooperating forces. As shown, as a result of the injection force, fluid is ejected from the fluid collection chamber through the outlet nozzle. Like in the open position of the valve, seal ring 134 prevents that the fluid flows in the backwards direction along a radially outer side of the piston rod when an injection force is applied on the fluid injection device, and ensures that all fluid collected in the fluid collection chamber is forced out of the fluid injection device.
[0078] FIGS. 8 and 9 schematically illustrate two alternative embodiments of a fluid injection assembly 100. In FIG. 8, coupler 14 of the fluid injection device 1 comprises a male Luer connector 143. This allows to couple the fluid injection device 1 with a fluid container 3 that is provided with a female Luer connector 41. For example, the fluid container 3 may be attached to an adapter 4, the adapter 4 comprising the female Luer connector 41.
[0079] In FIG. 9, the coupler 14 of the fluid injection device 1 comprises female Luer connector 41. This allows to couple the fluid injection device 1 with a syringe 5 that is provided with male Luer screw connector 51.
[0080] Shown in FIG. 10 is one possible way to manufacture a valve as described in the above. As shown in FIG. 10, a pre-moulded piston head 13, free of radial flow channels, may be fixed in a fixture 200. Knifes 201, 202 may then cut away some of the material of the piston head 13, to create the radial flow channel(s) at the desired location.
LIST OF REFERENCE NUMERALS
[0081] 1 Fluid injection device [0082] 11 cap [0083] 111 seal [0084] 112 coupling mechanism (female) [0085] 12 housing [0086] 121 outlet nozzle [0087] 122 fluid collection chamber [0088] 123 coupling mechanism (male) [0089] 124 inner wall of fluid collection chamber [0090] 13 piston head [0091] 131 valve [0092] 132 annular rim [0093] 133 radial flow channel [0094] 134 seal ring [0095] 135 piston rod receiving chamber [0096] 136 longitudinal flow channel [0097] 137 throughflow opening [0098] 14 coupler [0099] 141 snap finger [0100] 142 flange [0101] 143 male Luer connector [0102] 15 internal flow channel [0103] 151 fluid container facing end [0104] 152 piston head facing end [0105] 16 piston rod [0106] 17 threaded connection [0107] 3 fluid container [0108] 31 septum [0109] 32 cap [0110] 33 piston head [0111] 4 fluid container adapter [0112] 41 female Luer connector [0113] 42 container body [0114] 5 syringe [0115] 51 male Luer taper thread [0116] 52 stopper [0117] 100 assembly [0118] 200 fixture [0119] 201 knife [0120] 202 knife [0121] B backwards direction [0122] closed valve position [0123] F forwards direction [0124] F.sub.B force induced by movement in backwards direction [0125] F.sub.F friction force [0126] F.sub.I force induced by movement in injection direction [0127] IF injection fluid [0128] L longitudinal direction [0129] O open valve position
